Scotty_82

iTrader: (1)

My recently acquired L92 engine, wondering what all these #s are on the pistons. Especially curious about what looks like hand inscribed "14?" on one bank, "15?" on the other bank. I say hand inscribed, because on each piston they are slightly different, but still "14?" or "15?". Looks like they're centerpunched in. I thought it was strange.
Anyone know what this is all about?

Scotty_82

iTrader: (1)

OK, let me try something to get the full pictures up..... ah, I think I've got it now.
Again, looks like the marks were NOT made by a machine, and a crappy L92 sure isn't a hand built engine. And by all appearances, I was the first guy to ever pull the heads off this engine. But maybe these marking are the norm??

So thanks if someone can shed some light on this.


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cabel1

iTrader: (3)

Mine didn't have those

Che70velle

iTrader: (6)

Somebody's been in there for sure. Is it just me, or does that cylinder wall look very thin at the bottom of the pic?

1989GTA

Mine had markings similiar to those. Mine L92 came out of a 2009 Escalade.

Scotty_82

iTrader: (1)

Thanks for the feedback guys.
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Regarding someone being in there before, that would have been my first thought on seeing those hand-made markings, like maybe indicating a need for addn. honing, etc. Or, I thought maybe it was an engine pulled aside for a QC check.... if they even do that. But again, I'm no expert, but looks like the motor hasn't been apart, or should I say, not recently.
The sleeves? I think that's an illusion. By eye, all sleeves look equal. Moot point since the block is busted anyway (starter mount gone), apparent crash damage, which why I got it for real cheap.
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2009 Escalade? Good to know. I was "told" my engine is from a 2008 Escalade, yet it had AFM, and some say it wasn't yet available in Escalades in 2008??

Another mystery about this engine, Looks like it had run like **** for some time. Combustion chambers were crudded up somewhat, lots of black & wet. One sparkplug was even fouled. Inside the valve covers and crankcase, looks like brand new.

RezinTexas

the dots on the two ?'s are in the exact same pattern, too close to replicate by hand in my opinion. It looks like someone had a single punch to inscribe a "?".

Why someone would have that "?" punch is a total mystery to me...

-Joseph-

iTrader: (12)

That thinner cylinder wall is fairly normal on the 6.2L blocks. Not a fan or saying it's normal, but it's on just about all of them that I've ever seen.

Interesting markings, I never looked or have seen any. I'll be sure to look on the next one I tear into. I like parts that have a "?" on them, lol.

Jimbo1367

I thought L92s/LS3s didn't have valve reliefs.

1989GTA

L92's do because they have VVT.

Scotty_82

iTrader: (1)

I took a closer look at those markings, you are right. It DOES look like automated markings. Odd thing is, one or two look the same as others, just smaller, like a different font size.. LOL.
Further, two pistons have a crooked 1 in front of the 4 & 5s.... realized they too are the same as each other, so they are actually backslashes. So I have 15?, 14?, /5? and /4?, etc.

Regarding those marks, What's chances that this particular engine had a glitch during production. For instance, one or more cylinders needed to be overbored a tad, and those marks indicate something about oversize pistion and hone/fitting. OR, non-std. rod shells to compensate for a couple ten thou crank pin sizing glitch? Or, as I mentioned earlier, it was pulled aside during production for a QC check and those marks indicate results of skirt clearance specs, etc.